10 things you need to know before the opening bell

AP/Vincent YuPolice officers use pepper spray against protesters in a rally against the proposed amendments to the extradition law at the Legislative Council in Hong Kong.

Here is what you need to know.

China ramps up trade-war tensions. "If the United States only wants to escalate trade frictions, we will resolutely respond and fight to the end," Chinese Foreign Ministry spokesman Geng Shuang told Reuters.

The Chinese yuan climbs off 6-month lows. The offshore Chinese yuan is up 0.28% at 6.9119 per dollar after on Monday closing at its highest level since November.